A hole in one: Your guide to self-piercing grommets and washers

by carly_mchugh | 1 September 2022 3:20 pm

By Keith Gentilin

Since their first iteration more than 100 years ago, self-piercing grommets and washers have enabled smaller sign and banner shops to scale production, improve productivity, and ultimately increase their profit margins. This combination is the most beneficial when the material does not already have holes for fasteners, as there is no need to pre-punch holes in the material when using a bench press. The bench press and the self-piercing grommet do all the work upon pushing the lever down, creating reliable hole reinforcement in seconds. Most sign and banner materials—including corrugated plastic, vinyl, and polyester—are easy to pierce with minimal effort.

What are self-piercing grommets and washers?

Unlike traditional fastening systems, self-piercing grommets and washers are specially engineered to pierce the sign and banner material and set the grommet in one action. During the setting process, the interaction between the grommet and the washer safely punches a hole in the material and coils the washer in one stroke. The system works in tandem with the bench press, and the corresponding self-piercing die helps set fasteners securely, confidently, and quickly. High-quality grommets feature a smooth inside edge designed to reduce friction with the cord or rope and premature product failure for the end-user. Although self-piercing grommets and washers from different manufacturers perform similarly, it is essential to check the tooling since compatibility between manufacturers is not guaranteed.

What are they manufactured from?

High-quality, solid brass grommets and washers are manufactured from cartridge brass, which contains 70 per cent copper and 30 per cent zinc. Self-piercing grommets and washers with this metallurgical composition are incredibly durable while still retaining malleability. Since they are manufactured from a heavier gauge and higher quality brass than traditional sheet metal fastener combinations, self-piercing grommets and washers will withstand commercial indoor and outdoor environments for many years.

Another popular base metal for sign and banner applications is stainless steel. Reputable manufacturers and suppliers use Grade 304 stainless steel, which contains chromium as an alloying element to inhibit rust. Since they do not rust, stainless steel self-piercing grommets and washers maintain an attractive appearance regardless of environmental conditions, making them an ideal choice for outdoor signs and banners—especially in marine environments. Stainless steel contains a high percentage of chromium and will “self-repair” when scratched or damaged, increasing the service life of the grommets and washers. Whether the application requires brass or stainless steel fasteners, both base metals retain their attractive, modern appearance after installation and instantly enhance the esthetic of any sign or banner.

Exploring new profit centres with finishes

No two sign and banner jobs are alike; the customizations available today are almost endless. Customers can now select from various materials, print options, reinforced edges, and material thicknesses. As sign and banner customizations continue to grow in popularity, “decorative” grommet and washer finish options are an emerging trend and an untapped profit centre for many sign and banner professionals.

Manufacturers and suppliers offer different finish options—including plain brass, nickel plating, and dull black—to meet changing customer demands and strict adherence to their brand guidelines. Although considered decorative, finishes inhibit corrosion and oxidation, making them ideal for indoor and outdoor signs and banners.

Plain brass

Plain brass grommets and washers have remained a popular finish option for decades due to their bright, lustrous finish and golden hue. Sign and banner professionals rely on brass fasteners because of their durability in a variety of indoor and outdoor applications.

Nickel plating

Although it is similar in appearance to stainless steel, nickel plating is a popular grommet and washer finish option because it protects the fastener’s base metal and provides a lustrous finish. This finish offers excellent corrosion and wear resistance and is suitable for outdoor applications, including signs and banners in harsh marine environments. Unlike other decorative finishes, nickel plating ensures the base metal is protected even when components such as hanging clips, bungee cords with hooks, or metal cables slide across adjacent surfaces, including the grommet and washer.

Dull black

Another popular finish option is dull black. This type of finish is ideal for customers who want an all-black or dark-coloured sign or banner. This non-reflective, matte black colour meets military specifications, where the fasteners must reflect the absolute minimum amount of light. Instead of an electroplated finish, dull black is an oxide finish. Due to the oxidation process, dull black grommets and washers have additional corrosion and abrasion protection, making them suitable for indoor and outdoor sign and banner applications.

Sizing options for grommets and washers

The author’s company manufactures and inventories standard trade size brass and stainless steel self-piercing grommets and washers. Sizes include No. 0, No. 1, No. 2, No. 2XL, and No. 3. Although standard trade sizing is typical among manufacturers, it is vital to double-check the tooling compatibility. Figure 1 (above) provides essential sizing information for brass and stainless steel self-piercing grommets and washers, including hole sizing.

Grommets and washers for thicker materials  

Unusually thick signs and banners made from corrugated plastic or vinyl require a long-neck grommet and washer to securely fasten and display a sign or banner. While sizes may vary slightly between manufacturers, XL-length self-piercing grommets and washers typically feature an additional 7.6 mm (0.3 in.) of length under flange (LUF), making them an ideal fastening solution for materials up to 12.7 mm (0.5 in.) thick. Available in brass or stainless steel, extra-long grommets pierce the material and set the grommet in one single action. The extra 7.6 mm prevents experienced and inexperienced press operators from inadvertently compressing or “squishing” the material during the setting process. The additional length prevents accidental compression and damage to materials due to their extra size, which helps save time
and money.

Setting self-piercing grommets and washers

Setting self-piercing grommets and washers and swapping out tooling to accommodate different sizes of fasteners is easy with a bench press. After placing them on the appropriate tooling, it only takes one step—depressing the lever—to pierce a hole in the material and set self-piercing grommets and washers.

Should your shop use self-piercing grommets and washers?

To determine if self-piercing or sheet metal grommets are best for a shop’s operation, fastening professionals need to know several pieces of information. First, what type of grommets and washers has the shop historically used in its signs and banners? Second, what type of attaching machine does the shop currently use: a manual bench press or an automatic attaching machine? Third, what type of sign and banner material does the shop use most often: corrugated plastic, vinyl, or polyester? With this information, an experienced fastening professional can help a shop make an informed purchasing decision.

Smaller volume shops that use manual presses with one or two sign and banner material types will benefit from self-piercing grommets and washers since pre-punching a hole is unnecessary. Migrating to self-piercing grommets with a manual bench press is a tried-and-true option to boost productivity and profit margins. Larger sign and banner operations will also benefit from increased productivity when using self-piercing grommets paired with the proper automatic attaching machinery.

Keith Gentilin, director of sales and marketing for Stimpson, has more than 25 years of experience in sales, marketing, and customer service. He is responsible for managing the company’s sales staff, marketing programs, and customer-centric processes. Gentilin is dedicated and passionate about helping customers and the sales team solve complex fastening applications.

Source URL: https://www.signmedia.ca/a-hole-in-one-your-guide-to-self-piercing-grommets-and-washers/

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